In semiconductor fabrication processes, a single layer of features is sometimes formed by using multiple-exposure or multiple-patterning technology to improve a spatial resolution of the particular layer. For example, if a layer of features are to be fabricated using N exposure or patterning processes (i.e., N-exposure or N-patterning), N being a positive integer greater than 1, layout patterns corresponding to a layout design for the layer of features are assigned to N different masks for corresponding exposure or patterning processes. Actual features fabricated based on the N masks using the multiple-patterning technology and the layout patterns differ in their physical characteristics of components, such as size, shape, position, or electrical properties. For example, if N is set as two (2), a first mask is used to form a first set of metal components and a second mask is used to form a second set of metal components. After formation of a first set of metal components according to the first mask, a spacer structure is formed to surround the first set of metal components. The second mask and the spacer structure are subsequently used to define the second set of metal components. Any variation during the formation of the first set of metal components and the spacer structure would in turn affect the physical characteristics of the second set of metal components.